Knightmare.com

I also have the boardgame- All the rooms on it are from series 1-3. I think generally it is a good game though quite difficult. The riddles themselves seem to be ones that were actually asked in knightmare so I can get them right from time to time.

The books I have: Dragon's lair and Lord Fear's domain. Dragon's lair I have always preferred due to its imaginative role-playing nature. (Lord Fear's domain was just a puzzle book)  

They should  do models of the characters with room 'play-backgrounds', sort of like what they did with Mony Python and the Holy Grail.

I've got books 2-6 and the board game, which is quite good, if a little complicated for non-KM-knowledgeable people!  And then I've got *ahem* videos of Series 3, 4, 6 and soon 5...